Pre-Test

Which statement best describes Newton’s First Law of Motion?

• An object moves only when a force is applied to it.
  
  

• An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.

• Objects tend to move in circular motion unless stopped.
  
  

• A moving object will always stop due to friction.

How is mass related to inertia?

• The greater the mass, the greater the inertia.

• The greater the mass, the lesser the inertia.

• Mass and inertia are unrelated.
  
  

• Inertia only applies to moving objects.

A book is lying on a table and remains at rest. What force is keeping it from falling?

• Gravity is pulling it down, and friction is pushing it up.

• . Gravity is pulling it down, and the normal force from the table is pushing it up.

• Air resistance is preventing the book from falling.
  
  

• The book has no force acting on it.

In sports, why is it harder to stop a fast-moving soccer ball than a slow-moving one?

• A faster ball has less inertia.
  
  

• A faster ball has more inertia and requires a greater force to stop.

• A slower ball has more inertia and resists stopping.
  
  

• The force applied by the player determines inertia.

A truck and a bicycle are moving at the same speed. Which object is harder to stop and why?

• The bicycle, because it has less friction.
  
  

• The truck, because it has more mass and greater inertia.

• The bicycle, because it has greater acceleration.
  
  

• Both are equally hard to stop if they move at the same speed.